Sand blowing apparatus for making molds



June 24, 1958 H. J. B. HERBRUGGEN 2,839,799

' 1 sum BLOWING APPARATUS FOR MAKING MOLDS Filed Feb. 14, 1955 4 Sheets-Sheet 1 INVENTOR.

June 24, 1958 H. J. B. HERBRUGGEN 2,839,799

SAND BLOWING APPARATUS FOR MAKING MOLDS Filed Feb. 14, 1955 4 Sheets-Sheet 2 IN V EN TOR.

H. J. B. HERBRUGGEN 4 Sheets-Sheet 3 June 24, 1958 SAND BLOWING APPARATUS FOR xvmxmc; MOLDS E l/ l :50

Filed Feb. 14, 1955 "mm r E 57 1 T 3f 2 W L.- 1 I INVENTOR.

i [Ink/x124 J5 flflKb/VLIGQEN j BY mww June 24, 1958 H. J. B. HERBRUGGEN 2,839,799

SAND BLOWING APPARATUS FOR MAKING MOLDS Filed Feb. 14, 1955- 4 Sheets-Sheet 4 BY MW the frame and at a lower moreaccessible level.

United States Patent 9 SAND BLOWINGVAPPARATUS FOR MAKING MOLDS Application February 14, 1955, Serial No. 487,963

2 Claims. (Cl. 22-36) This invention relates to a sand blowing apparatus for making foundry cores and molds and more particularly relates to an improved arrangement for making and discharging the completed molds.

,In the usual sand. blowing apparatus the flask is supported on a bottom plate beneath a top blow plate through which sand is blown by means of an air stream from a sand transfer chamber. Usually the top and bottom plates are carried by the sand transfer chamber and by the lift piston respectively and are movable toward each other to close the top and bottom of the flask and form a mold cavity therein. Sand'is then blowninto the cavity under suitable pressure to pack it around a pattern carried by either or both the top and bottom plates, de-' pending upon whether the apparatus is being used to form simple or multiple molds. After the mold has been blown the plates are separated and an operator removes the flask with its completed mold. In the case oflarge size molds the weight of the completed mold unduly burdens the operator, and it'is a principal object of this invention to minimize this burden by providing .a mechanical arrangement to assist the operator in loading and discharging the flask. n

Another object of this invention relates tothe provision of an improved arrangement forcompacting the sand about the pattern within the mold cavity by "moving one of the plates relative to the flask and other plate in a sand compacting direction. Briefly, this invention is adapted to the environment of a conventional sand blowing apparatus which may be of the type having an overhead frame which carries a sand transfer chamber in surmounting relation over a flask lift piston along with suitable conduits and controls .for supplying an air stream to the transfer chamber... At one side of the frame is a parallel linkage arrangement which carries a-flask supporting tray that may be positioned into the work space between the lift piston and the sand transfer chamber and then returned to a location external of The lift piston, in addition to'means for supporting theflask, also carries an independently movable bottom plate which can be selectively positioned ina sand compacting direction within the flask. The mechanical flask loadingtand discharge mechanism greatly .minimizes the effort required by an operator in handling the completed molds bygiving him access to a mechanical advantage for removing the completed mold from the loading area to a more accessible and convenient location external to the apparatus frame.

Fig. 1 is an operators view of the sand blowing ap- 'paratus of this invention;

Fig. 2 is aside elevation of the lower portion ofthe apparatus illustrating the flask loading and discharge mechanism in the loading position; I

Fig. 3 is also a side'elevation of the'lower portion of the apparatus illustrating'the flask loading'and discharg mechanism in the discharge position; I

F ice Fig. 4 is a front elevation of the lower portion of the apparatus from the operators standpoint illustrating the flask loading and discharge mechanism in the loading position; and

' Fig. 5 is a view of the loading area of the apparatus illustrating in partial section the operative disposition of the lift and compacting mechanism in relation to the flask and the sand transfer chamber blow plate.

Referring now to Fig. l of the drawings, there is shown an operators view of the sand blowing apparatus which embodies a base supporting spaced columns 11 and 12 which are interconnected at the top by a crosshead 13 to form an overhead frame for a loading and operating area. The base 10 supports a lift platen 15 which may be positioned in a vertical direction by the application of hydraulic pressure to a piston in the base housing 16. The platen 15 supports a bottom plate 17 which is independen tly movable in a vertical direction in a manner and for a purpose to be hereinafter more fully described.

The platen assembly including the bottom plate 17 is intended to lift a flask 18 upwardly against a top vent plate 19 which is part of the blow plate assembly for a sand transfer chamber 20. The chamber 20 is supported by suitable arms such as indicated at 21 for limited swinging and vertical movement on the column 12. Air conduits like 23 and control valves like 24 are provided to supply a controlled air stream to the sand transfer chamber 20 from a suitable source of air pressure through the control panel 25. In a conventional sand blowing apparatus, the control panel. 25 and a control valve such as shown at 24 cooperate to provide an automatic sand blowing cycle to blow the sand from the transfer chamber into the mold cavity in the flask 18. The blowing pressure is vented through the vent plate 19 and when the cycle is terminated the remaining pressure is exhausted from the chamber 20 through the stack shown at 26.

After the flask 18 hasbeen filled with sand to form a suitable core or mold it must be lifted out of the loading area between the top and bottom pattern plates and stacked for pouring. In order to minimize the lifting effort and reduce the operators burden, the flask 18 is shown supported on atray 30 which may be mechanically positioned into and out of the loading area in accordance with this invention by means of a parallel linkage arrangement in a manner to be hereinafter more fully described.

Referring now more particularly to the lower portion of the apparatus in Fig. l, as shown in side elevation in Figs. 2 and 3 of the drawings, the flask supporting tray 30 is shown carried at one extremity of links 31 and 32, the other extremity of these links being connected respectively to a rocker shaft 33 and a pivot pin 34 which projects from a side plate 36 fixed to the base 10. This linkage arrangement is duplicated on the other side of the apparatus frame and it will be understood that the description of the links 31 and 32 and their coaction between the tray 30 and the base 10 of the apparatus, although limited to the side viewed in Figs. 2 and 3 of the drawings, is identical on the other side of the apparatus.

As best shown'in Figs. land 3, a bell crank arm 35 is fixed,as by a key or similar arrangement, to the rocker shaft 33 to which the other extremity of the link 31 is connected. The extended portion of the arm 35 is pivotally connected at 42 to the plunger 43 of a hydraulically operated piston which, though not shown, is operatively positioned within a cylinder 46 mounted on the side of the base 10. In order to accommodate the translation from straight line motion of the piston plunger 43 to circular motion of the arm 35, the mounting of the piston assembly including the cylinder 46 to the base 10 is made through a pivotal connection 48 to a bracket 50 fixed on the base 10. Fluid operating pressure is supplied to the cylinder by connecting conduits 51 and 52'frorn twin oil tanks carried in a housing 53. The conduit connections are through couplings which permit free movement of the pivotal cylinder 46.

The connection between the links 31 and 32 andthe tray '39 is by means of pivot pins 54' and 55 'whieh'are spaced the same distance apart from each othenas-the rocker shaft 33 is spaced from the pivotal connection '34 of the link 32 to the side plate 36. Similarly, thestraight line distances between the link connections to the side plate 36 and the corresponding link connections to the tray 39 are equal for'each link, thus effectively forming a parallel link arrangement for maintaining the'flask supporting tray 30 level while moving it between the flask loading area and'the flask discharge position. Positioning ofthe linkage system is accomplished by controlled application'of hydraulic pressure to the cylinder 46 to position the piston plunger .43 for rotationof the bell crank arm andshaft in the desired direction. The link 31, being fixed on the rocker shaftyis the prime mover in the iinkage system while the link 32 is a follower type link for maintaining the tray 38in a level position as it is moved between the loading and discharge positions. The non-linear configuration of the links shown in the drawings is for mechanical clearance during operation of the linkage system, as is readily apparent by comparing the side elevations of the linkage arrangement in Figs. 2 and 3 with the front elevation shown in Fig. 4-of the drawings. The link 32 also has an outwardly directed rib 57 which is adapted to rest on the surface of the bell crank arm 35 when the tray 3% is moved tothe discharge position shown in Fig. 3. This provides a'positivestop for the -linkage system when the tray 30 is located external to the overhead frame and at a level which is convenient for lifting a completed flask and mold from the tray, thus minimizing the eflort and reducing the'burden on the operator during removal of the completed mold from-the apparatus.

Referring now more particularly to Fig. of the drawings, which illustrates in greater detail the operative elements in the loading areaof the sand blowingapparatus, the lift platen carries vertical studs 59 which support a flask platform 6* having an annular top that is a facsimile of the peripheral boundary wall of the flask i8.

Suitable guide pins 61 are secured in the top of the plat form of for engagment in bushings 63 carried by apertures in the boundarywall of the flask. This assures proper alignment of the interior wall surface of the flask 18 with the interior wall surface of the platform 60 to permit free movement of the bottom pattern plate into flask opening for sand compacting purposes. The bottom pattern plate 2? is in turn secured on a spider-like supplementary platen 65 which is mounted for vertical movement on a mast-like projection 68 secured to the lower platen 15. Both the platens 15' and 65 are keyed against rotation relative to each other by means of suitable pins 67, one end of which is doweled into the platen i5 and the other end of which extends into suitable receiving apertures 69 in the lower face of the supplementary platen 65.

In operation, the platen 15 is hydraulically positioned to lift the entire platen assembly including the flask'platform 6!) and the supplemental platen 65 along withthe flask i8 upwardly against the vent plate 19 as shown by the dotted lines in Fig. 5 of the drawings. Once the flask 18has been properly positioned so that the top and bottom plates enclose the flask boundaries to provide a mold cavity, the air pressure may be selectively applied to the sand transfer chamber to force sand through the openings 70 into the mold cavity. After the mold cavity has been filled, pressure may be supplied to the passageway '72 in the platen 15 to lift the supplementary platen 65 and the bottom pattern plate '17 into the-mold cavity to squeeze and compact the sand within the cavity, thus assuring that the sand is sufliciently hard to resist 'the deformation.

Thereafter, pressure may be removed from the supplementary platen and from the lift platen 15 to separate the flask from the top and bottom plates and permit its removal in the manner hereinbefore described.

The ease with which theoperat'or can handle completed molds-makes it possible to make a large numberof'rnolds in a very short time and with comparatively little manual labor. This results in economy of operation with a high production'rate. In like manner, theimproved squeezeplatc'ass'embly contributes to the increased produeti'onin addition'to performing its principal function of assuring sand molds that will. come up to thehiglrstandards in foundry practice.

I have shownan'd described'what I consider to be the preferred embodiments of my invention along with similar modified forms and suggestions, and it will be obvious to those skilled'in the art that other chan'ges'and modifications may be madewithout departing from the scope of this invention as defined by the'appended claims.

I claim:

1. In a sand blowing apparatus having a frame including a flask-supporting base surmounted by a sand transfer chamber and defining a flask-receiving work area therebetween, a flask supporting tray, fluid pressure aetuated means on 'the frame for selectively moving said tray into and away from operative position'in the flaskreceiving work area, said sand transfer chamber having a base with a sand discharge opening therein, a main lift platen operatively carried by the flask supporting base, a supplementary'platen operatively carried for relative vertical movement on said main lift platen,'means on said platens for preventing relative'rotational move-v ment therebetween, said supplementary platen having a configuration adapted to support a bottom pattern plate for positioning into the flask, a flask platform fixedly carried by said main platen, said platform presenting a flask supporting surface that is a facsimile of the flask wall'boundar-y and surrounding said supplementaryplaten, means carried by the flask supporting surfaceof said platform for aligning coaction-with the flask when the latter is disposed on said tray in 'said flask work area, fluid pressure meansfor selectively raising themain lift platen whereby said platform is lifted into abutment with the bottom of said flask and said flask is positioned against the base of'said sand transfer cham'ben-andother fluid pressure means for selectively positioning'the supplementary platenand'pattern plate into the flask to com-pact the sand therein. I

2. In a sand blowing apparatus having a vertical frame including a raised flask supporting base surmounted by a sand transfer chamber and defining afl-ask receiving work area therebetween, a flask supporting tray adapted to be moved into and away fromthe flask work area,-a shaft journaled on the'frame for rotation in the direction of tray movement, a-parallel linkage system having a pair of links for movably supporting the tray on the frame, one end of one of said links being keyed to said shaft'and one-end of the other of said links being pivotally mounted on the'frame and in spaced relation from said shaft in the'direction of tray movement, the other end of each link-being pivotally connected to the trayat 'pointsspaced from each other in'the direction of tray movement a distance sufiicient to define a parallelogram between the pivotal connections including the connection of said one link to the shaft, a lever. keyed on one end thereof to'said' shaft and having its other end coupled to a fluid operated piston and cylinder unit for selectively rotating said shaft to move said tray in horizontal condition towards and away from the flask work area, said sand transfer chamber having a base with-a sand discharge=opening therein, a main-lift platen operatively carried by said flask supporting base, a supplementary platen operativelycarried-for relative vertical movement on said main lift platen, means on said platens for preventing relative rotational movement therebetween, said supplementary platen having a configuration adapted to support a bottom pattern plate for positioning in the flask, a flask platform fixedly carried by said main lift platen, said platform presenting a flask supporting surface that is a facsimile of the flask wall boundary and surrounding said supplementary platen, means carried by the flask supporting surface of said platform for aligning coaction with the flask when the latter is disposed on said tray in said flask work area,

said last mentioned means comprising a plurality of upright pins secured to the top of said platform and adapted for entry to complementary openings in said flask when said platform is moved towards engagement with the under side of said flask, fluid pressure means for selectively raising the main lift platen whereby said platform is lifted into abutment with the bottom of said flask and said flask is lifted from said tray and positioned against 6 the base of said sand transfer chamber, and other fluid pressure means for selectively positioning the supplementary platen and supported pattern plate into the flask to compact the sand therein.

References Cited in the file of this patent UNITED STATES PATENTS 778,329 Pipher Dec. 27, 1904 1,803,406 Ringle May 5, 1931 1,931,185 Firestone Oct. 17, 1933 2,191,451 Campbell Feb. 27, 1940 2,349,219 Wood May 16, 1944 2,656,575 Herbruggen Oct. 27, 1953 2,757,424 Daniel et a1. Aug. 7, 1956 2,785,447 Anderson Mar. 19, 1957 2,791,013 Demmler May 7, 1957 

